18-inch necklace. If you saw the movie Tin Cup, you likely remember the great pearl necklace Rene Russo wore throughout the film. We know we did! Crafted with with luminous creamy white freshwater cultured 8mm pearls and a delicate 18K white gold plated .925 sterling silver snake chain, Moon River Pearls' Tin Cup necklace should not be confused with less expensive options. A wise investment, this is a high-quality piece made with genuine cultured pearls. Equally elegant whether you pair it with a turtleneck or a cocktail dress, this versatile necklace has become an instant classic, not to mention one of the favorite pieces in our bridal jewelry collection. 16-inch style - see below. Spring ring clasp.